In recent years, personal computers (hereinafter referred to as PCs) have been becoming more popular, and more and more recorders, such as digital versatile disc (DVD) recorders and hard disc recorders, and televisions are provided with a function of network connection. In addition, broadband connection services have been becoming less expensive. Such changes have been promoting the use of home networks.
Home networks are built using a variety of connection methods including not only a wired local area network (LAN) in which devices are interconnected using Ethernet (Ethernet is a registered trademark) cable but also new types of networks such as a wireless LAN and power line communication (hereinafter referred to as PLC) system, which allow connections of devices without introducing additional cables to home.
In such a communication environment, it may be impossible for users to have a network of desirable communication quality because the media have different transmission speeds and different sensitivities to interference of radio waves. Such differences are due to differences in properties among the communication media of the Ethernet connection, the wireless LAN, and the PLC system. Because not all the users of home networks are familiar with such network technologies, troubles in installation of devices on a network and network failures are often difficult for them to solve.
To solve the problems, it is desired that a communication status or a configuration of a home network can be easily identified at home or from a remote location. The remote location is, for example, a call center of a device manufacturer or a broadband connection service provider.
A conventional technique to solve the problems is disclosed in PTL 1. Specifically, PTL 1 discloses a technique in which bandwidths of communication between two devices on a network are measured when Transmission Control Protocol (TCP) packets are used and when User Datagram Protocol (UDP) packets are used, and presence of a wireless section between the two devices on the network is determined depending on whether or not the difference between the bandwidths exceeds a predetermined threshold.